Telephone-system.



W. W. DEAN.

TELEPHONE SYSTEM. APPLICATION FILED 001. 11, 1900.

I 950,896. I Patented "Mar. 1, 1910.

UNITED STATES- PATENT OFFICE.

WILLIAM W. DEAN, OF CHICAGO, ILLINOIS, 'ASSIGNOR, BY MESNE ASSIGNMENTS, TO CONSOLIDATED FIRE ALARM COMPANY, OF NEW YORK, N. Y., A CORPORATION OF new YORK.

TELEPHONE SYSTEM.

To all whom it may concern:

Be it known that I, VVILLIAM W. DEAN,

I citizen of the United States, residing at Chicago, in the countyof Cook and State of Illinois, have invented a certain new and useful Improvementin Telephone *Systems, (Case 1,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to telephone systems, and has for its object the provision of means whereby the telephone lines may be employed in the service of synchronizing and winding clocks that may be located at the diiferent substations of an exchange.

By means of my invention, I am able to synchronize and wind clocks that may be located-at a large number of telephone substations by means of a single master clock located at the exchange. To this end I provide the individual telephone lines with -"connecti'ons that serve to unite them all to so that the subscribers may not be annoyed.

by the violent operation of the receiver diaphragms that might occur upon the transmission of such an impulse.

' \Vhile I have devised a system in which .the clocksare synchronized and wound by a common means, I do not .wish to be limited to a system 'in which both of these functions are accomplished. I will explain my invention more fully b reference to the accompanying drawing, in

Figure 1 is a diagram illustrative of a telephone exchange system provided with the apparatus of my invention; Fig. 2 is a detailed view of a substation apparatus for synchronizing and winding clocks in accordance with my invention.

the battery Specification of Letters Patent. Patented Mar. 1, 1910. Application filed October 11, 1900;

Serial No. 82,708.

I Like parts are indicated by similar char-- acters of reference in the views.

I have illustrated one form of telephone system, two substations being illustrated, at each of which is located a switch-hook a, a receiver b, a transmitter cfand a call-bell d included in series with the condenser e, the call-bell and condenser being included in bridge between the sides of the telephone extend respectively to the short and long line springs of spring-jacks G at the exchange. A well known form of cord-connecting apparatus is illustrated at the exchange H, switch plugs 7L and 5 having connected tips, connected sleeves and connected heel pieces grounded through a battery is, the heel pieces being adapted for electrical connection, with the thimbles Z Z of the spring-jacks G, for the purpose of completing circuit through the cut-off relays m m, the test thimbles constituting terminals of these relays, the other-terminals of which are grounded.

The telephone exchange thus far described is sunilar to ,the ordinary form of telephone exchange at present in use. The

with the substation apparatus, are also connected with armatures s and t of the cut-off relay 'm, which armatures, when lying against their normal contact, include in cir cuit with the indicator '0, the common calling battery u. The telephone lines f and g are normally disconnected at the substation, the only connection between them being through the condenser e which does not permit of a flow of direct current when the switch hook is raised to complete the metallic circuit between the limbs f and g. The current from u flows through the indicator o, attracts t e armature thereof, and, lights the indicating lamp associated therewith. When a plug 73 is inserted in the springjack G, the cut-off relay m is energized by having the circuit pass therethrough from a ground, through battery 1:, the sleeve of the plug 2', the thimble Z, the energizing coil m, back to theground, and thereby attracting both armatures s and t, 'thuscutting off the lines 7' and 'g from the calling battery u I and permitting said lines to" have a clear metallic connection to another subscribers lines f and g. The telephone lines f and g telephone lines 7 and g which are connected.

line through the cord connecting apparatus. My invention, however, is adapted for use with any well known form of telephone systern to which it may be applied, and the particular circuits herein illustrated do not form part of my present invention. y

I will first describe the electrical arrangement of the master clock n at the exchange, and will then set forth its cooperative association with the telephone exchange system. The synchronizing cldcks illustrated are adapted to be synchronized once each hour, the minute hand of the master clock serving to close circuit through the magnet 0 and battery p once each hour, terminals of the circuit including the said magnet and battery being closed by the minute hand of the master clock each hour. The armature g of the master clock is normally in engagement with a contact arm, which contact connects the armature t with a ground connection, at the same time connecting said armature with the grounded side of the common calling battery u. The armature s when resting against its normal contact, is connected to the ungrounded terminal of the battery u through the line indicating relay '1). It will thus be seen that the lines f and g, by virtue of their connection with the armatures s and t and the armature 9 when unattracted, are connected in shunt circuit with the calling battery u, the circuit beingtraced from the line f through the armature t, the connecting wire t, the armature g, normal contact r, to the terminal of the battery which l is grounded at u, through said battery u by means of the connecting wire 8', through the line relay '0, and the armature s, to the hue 1 lines In this condition circuit may be closed through the relay 1) and the battery u by the removal of the telephone receiver from the switch hook at the subscriber's station when the subscribers cator of the battery, to the line g having been traced, it will be evident that by close circuiting the lines f and 1 at the substation, the circuit is completed and a removal of the switch hook will occasion an illumination of the line indicator associated with the line relay '0. The armature p is provided with an alternate contact anvil w which is connected with the ungrounded terminal of the battery u.

\Vhen the telephone lines of the subscribers are in their normal idle condition, and the master clock efiects the operation of the magnet 0, the armature g is shifted from its normal to its alternate contact to open the metallic circuitincluding the battery 24 and limit the current flowing from the said battery to a grounded circuit, which may be traced from the ground upon the said battery, through the battery, the alternate contact w, the armature g, the armatures t, the

initiate calls. 3 The circuit from the line f through the indif, the telephone switch-hooks a, and the grounded branches at the substations including the magnets 00 located at the substations, which, ln this instance, perform the double function of synchronizing the clocks at the substations and winding the same. When the telephone lines are not busy, the lines 7 are normally connected to the ground through the relays 0c, and when the synchronizing or master clock a energizes the relay 0, the other terminal of the line f is also connected to the-ground but through the battery u, thus sending a synchronizing impulse over the line.

The armatures of the magnets :20 are provided with synchronizing devices at their free ends of any Well known construction, that, in this instance, are provided with cam surfaces that engage pins y carried upon the minute hands of the subscribers clocks, these pins serving to bring the minute hands to iegister with the proper points upon the dials each time the armatures of the magnets to are actuated. The armatures of the said magnets also preferably carry pawls 2 that engage winding ratchet wheels that serve to wind the clocks each time the said armatures are actuated, in addition to synchronizing the same. When the subscribers are united for conversation, the relays m will be energized to attract the armatures s and t to remove the battery it electrically from the telephone lines 7 and g, While the plugs i at the same time include the battery 7c in parallel between the two lines f and g of the subscribers talking circuit. The telephone switches a at the substations, which are employed to normally ground the lines f through the relays thus serve when in an elevated position, to disconnect said telephone line f from the ground, so that no synchronizing impulse can be transmitted over said telephone line by the grounded battery 7/, and it is thus impossible for the master clock m to transmit synchronizing impulses over the line 7', current nevertheless passing over the lines f and g from the battery iv, which current is employed for talking purposes, but which current does not in any way serve to actuate the relay av. The connections that unite the subscribers lines, whereby the synchronizing master clock may be made common to a group of lines, are preferably normally permanent, while the lines are not in use.

It will thus be apparent that by means of the construction hereinbefore set forth, I am enabled to electrically unite a plurality of subscribers telephone lines with a master clock, which connection is normally intact so that synchronizing impulses may be transmitted over said telephone lines when the said telephone lines are not in use,-that is, no switching mechanism is necessary to connect the master or synchronizing clock with ion the auxiliary or subscribers clocks, in convention, but it is obvious thatother embodiments thereof may be devised without departing from the spirit thereof, and I do not, therefore, Wish to be limited to the precise disclosure herein set forth, but

Having described my invention, I claim as new and desire to secure by Letters'Patent: g r

I '1. The combination with telephone lines cxtending from subscribers stations to a central otiice, of a central source of current with which the lines are connected, switching apparatus at the central oflice for at any time establishing connections with the lines for conversational purposes, means for sending current from said source over the lines at stated intervals, devices located upon the lines responsive to such intermittently sent current, and further means for preventing the application of such current to the lines while connected for conversation, substantially as described. 7

2. The combination with telephone lines cxtending from subscribers stations to a central ofiice, of switching apparatus at the central office for at, any time establishing connections with the lines for conversational purposes, means for normally and automatically applying current to the lines at stated intervals, devices located upon the lines responsive to such applied currents, and further means for preventing the application of such current to the lines while they are connected for conversation, substantially as described.

The combination with telephone lines extending from subscribers stations to a central otiice, of switching apparatus at the central ofiice for at any time establishing connections with the lines for conversational purposes, means for applying current to the lines at stated intervals, devices located upon the lines responsive to such applied current, and means automatically actuated for preventing the application of such current to the lines while they are connected for conversation, substantially as described.

4. The combination with telephone lines extending from subscribers stations to a central office. of switching apparatus at central oflice for establishing connections with the lines for conversational purposes, means for normally applying current to the lines at stated intervals, devices located upon the lines responsive to such applied current,

and means automatically actuated by the act of establishing connections with the lines for preventing the application of such current to the lines while they are connected for conversation, substantially as described.

5. The combination with telephone lines extending from subscribers stations to a central oflice, of switching apparatus at the central office for at any time establishing connections with the lines for conversational purposes, means for applying synchronizing current to the lines at stated intervals, de vices located upon the lines adapted to be synchronized by such current, and further means for preventing the application of syn' chronizing currentto the lines while they are busy, substantially as described.

6. The combination with telephone lines extending from subscribers stations to a central oflice, of switching apparatus at the central ofiice for at any time establishing connections with the lines for conversational purposes, means for normally applying current to the lines at stated intervals, motor actuated devices located upon the lines, the motors of which are adapted to be wound by said applied current, and further means for preventing the application of such current to the lines While they are connected for conversation, substantially as described.

7. The combination with telephone lines extending from subscribers stations to a central ofiice, of a central source of current with which said lines are connected, a master clock arranged to send current from said source over the lines at stated inter'vals,individual clocks upon the lines adapted to be controlled by such intermittent current,

switching apparatus at the central office for establishing connections with the lines torconnections with the lines for con vcrsational purposes, means for normally applying current to the lines at stated intervals, motor actuated devices located upon the lines and arranged to be both synchronized and wound by said applied current. and further means for preventing the application of said current to the lines while theyare connected for conversation, substantially as described.

9. The combination with telephone lines extending from subscribers stations to a central office, of subscribers sets at the sol stations, a common source of current at the central office adapted for use with said lines for telephonic purposes, switching apparatus at the central office for-at any time establishing connections with the lines for conversational purposes, means for automatically sending current outv over the said lines at stated intervals, and devices located upon the lines responsive to said. intermittently sent currents but prevented from operation by the telephone signaling and talking currents, substantially as described. i 10. The combination with a telephone lin extending from a subscribers station to the central oflice, of a subscribers telephone set at the substation, a common source of current at the central oflice with which the line is connected, switching apparatus at the central oflice for at any time establishing connections with the line for conversational purposes, means at the central office for sending current from said source over the line at stated intervals, devices located upon the line responsive to said intermittently sent current, and a magnet energized during telephone connections with the line to prevent the flow of said intermittent current from said source to the line to prevent disturb ance therefrom during conversation, substantially as described.

11. The combination with telephone lines extending from subscribers stations to the central office, of line signals for the lines, cut-off electromagnets adapted to be energized during connections for conversation to render said signals inoperative, a central and common source of current adapted for use with the said lines for telephonic purposes, switching apparatus at the central oflice for at any time establishing connections with the lines for conversational purposes, means for sending current out over the lines at stated intervals. devices located upon the lines responsive to said intermittently sent currents, and means controlled by said cut-off magnets for preventing the applicaticn of said intermittent current to the lines while connected for conversation, substantially as described.

12. The combination with metallic telephone lines extending from subscribers stations to the central ofiice, of a line signal for each line at the central office, a common source of current at the central office to s which said lines are normally connected, a

switch at each substation adapted when operated to permit the flow of current from said source over one side of the metallic line to cause the operation of-the line signal of that line, means for causing a flow of current from said source at stated intervals over said lines for conversation, substantially as described.

ozstteee 13. The combination with metallic telephone lines extending from substations to a central office, means for automatically connecting a sourceof current between ground or common return and on side of the metallic lines at stated intervals, devices located upon the lines, and connected between the said side of the lines and ground or the common return so as to be operated by said intermittently sent currents, switching apparatus atthe central oflice to establish connections with the lines for conversation, a central source of current included in said apparatus and adapted to be introduced into the metallic lines to furnish current to the substations for talking, said latter source having one pole grounded or connected to the said common return, said latter pole when the connection is established being connected with the same side of the lines as said devices whereby said devices are not operated by the said source during connections, substantially as described.

14:. The combination with telephone lines extending from subscribers stations to a central ofiice, of a central common source of current to which said lines are connected for telc honic purposes, of switching apparatus at the central oflice for establishing connections with the lines for conversational purposes, means for automatically applying current to the lines at stated intervals, means to prevent disturbance to the subscribers thereby, and motor actuated devices located upon the lines and adapted to be controlled by said intermittently applied current, sub stantially as described.

15. The combination with telephone lines extending from subscribers stations to the central ofiice, of a common source of current with which the lines are connected at the central ofiice for telephonic urposes, telephonetransmitters at the su stations adapted for operation by current over the telephone lines from the central oflice, switching apparatus at the central office for establishing connections between the various lines for conversation, means for automatically sending cnrrent over the lines at stated intervals, means-to prevent said current from passing over a line when it is energized or in use, and devices located upon the lines responsive to such intermittently sent currents, substantially as described.

16. The combination with telephone lines extending from subscribers stations to the central oflice, of switching apparatus at the central office for establishing connections with the lines for conversation, means for applying current to the lines at stated inter vals, devices at the substations of the lines responsive to 'such, applied current, and switches "at the substations to cut out said devices during'the use of the subscribers telephones, substantially as described.

' cuit of the said device at each substation emcee 17. The combination with tele hone lines extending from subscribersstatlons to the central oflice, of switching apparatus at the, central ofiice for establishing connections with the lines for conversation, means for automatically applying current to the lines at stated intervals, devices at the substations of the lines responsive to such applied currents, a hook switch at each substation to change the line from normal condition to talking condition and vice-versa in the use of the subscribers" telephones, and means controlled by said hook switch to prevent the operation ofthe corresponding device dur-- ing the use of the telephone, substantially as described.

18-. The combination with telephone lines extending from subscribers stations to the central office, of switching apparatus at the central ofiice for establishing connections with the lines for conversation, means for applying current .to the lines at stated intervals, devices at; the substations of the lines responsive to such applied current, and

a hook switch at each'substation, the cirbeing completed through normal contacts of 5 said hook switch whereby when the receiver i 19. The combination with a plurality of telephone lines extending from the subscribers stations to the central ofiice of the exchange, of a central source of current having a common connection tosaid lines, a relay at the central ofiice having normal contacts in the common connection of said battery, with the lines and alternate contacts in a'common connection from said source to exists for conversation to sever the normalconnection of the corresponding lines-with said source whereby said Intermittent currentsare not sent over thetelephone lines stantially as described.

In witness whereof, I hereunto subscribe with which connection is established, submy name this ninth day of October A. D., I

WILLIAM W. DEAN.

Witnesses:

GEORGE L. CRAGG, HARVEY L. HANSON. 

